Well injection and bleed valve



Dec. 4, 1962 ca. H. TAUscH 3,066,690

wELL INJECTION AND BLEED VALVE Filed oct. 1e, 1959 2 sheets-sheet 1 6.Tausch INVENTOR.

Y Qchawj Dec. 4, 1962 G. H. TAUSCH 3,066,690

WELL INJECTION AND BLEED VALVE Filed OCT.. 16, 1959 2 Sheets-Sheet 2 G.h. T cn/Jc INVENTOR.

BY Qc; /QM

United States Patent Oilice 3,056,690 Patented Dec. 4, i962 3,066,690WELL llNltCTlN AND ELEED VALVE Gilbert H. Tausch, Houston, Tex.,assigner to Camco, lncorporated, Houston, Terr., a corporation of TexasFiled (let. 16, 1959, Ser. No. 346,921 7 Claims. (Cl. 137-155) Thisinvention relates to a well fluid production system having a productionconduit communicating with the bottom of a storage chamber into whichwell huid from an adjacent formation enters through a standing valve anderiodically is lifted to the surface by pressure gas injection into thechamber above its point of communication with the production conduit,and more particularly to an improved pressure responsive valve operatingautomatically to vent the upper end of the collecting chamber betweenlift phases of the operating cycle and to close the vent andconcurrently open the chamber for delivery thereto of pressure lift gas.

An object of the invention is to provide an improved well chamberinstallation by the use or a double acting valve which in the intervalbetween gas lift periods closes the pressure gas passage and vents thetop of the chamber into the production conduit to avoid air entrapmentand resistance to free flow of well fluid into the chamber above thebottom of the production conduit but which valve acts in response toimposition thereon of a predetermined lift gas pressure andsubstantially simultaneously opens the pressure delivery passage andcloses the vent so as to decrease and preclude pressure loss through thevent and make available full gas pressure for the utmost work of quicklyevacuating fluid from the chamber and moving the fluid to the surface.

A further object of the invention is to provide an improved ilow controldevice in which a valve head is movably enclosed within a cage and hasspaced apart and oppositely facing seats alternately engageable with avent port seat and a pressure delivery passage seat.

Another object of the invention is to provide a valve normally yieldablybiased away from vent closing position and toward pressure gas passageclosing relation and has an area exposed within the passage to theaction thereon of pressure gas and movement against the biasing force ata predeter iii-red gas pressure level, together with a valve engageableseat controlling the pressure gas passage and being itself movable inresponse to gas pressure for a folios -up action or unisonal movementwith the downstream moving valve to maintain passage closing relationthroughout an initial portion of the range of valve travel toward ventclosing relation and which valve seat at the end or unisonal travel andupon occurrence of an open crack at the valve seat immediately exposesto the pressure gas a surface area larger and facing oppositely to theaforementioned face for overbalancing the latter and causing snapreversal of movement direction and a quick opening of the passage tomaximum size and approximately coincident with vent closing action ofthe valve.

A still further object of the invention is to provide an assembly whosevalve normally is positioned to open the vent and close the pressure gaspassage in response to a biasinf7 force consisting of elastic gasconfined under pressure within a variable volume chamber formed betweenrelatively movable parts of the valve and valve housing and whichchamber also confines a liquid to be forced upon variation in chambervolume through a constricted orifice for restricting the rate of chambervolume change and for minimizing violent valve seat pounding andattendant wear and vibration fatigue of the parts.

In the accompanying drawing, FIG. 1 is a vertical section of a fragmentof the lower end of a well installation somewhat tdiagrammaticallyrepresenting an application of the present invention; FIGS. 2A and 2Bare companion views partly in side elevation and partly in verticalsection of a valve unit retrievably located within a side tubularreceiver of a tubing string section having a lateral offset and are on alarge scale; FIGS. 3 and 4 show fragments of the valve unit in elevationand vertical section to illustrate parts positions different from oneanother and from FiG. 2B; FlG. 5 on a large scale shows a tubing mandrelin vertical section and a nonretrievable valve unit mounted exterior-lythereof and FlG. 6 is a transverse section on line 6 6 of FIG. 3.

There is contemplated the conventional surface controller forintermittently shutting olf and delivering pressure lift gas or air intoa conduit leading downwardly to the well fluid collecting chamber andconveniently the conduit can be provided by the annular space l occuringbetween the production tubing string 2 and the well bore casing 3, asshown in FlG. l. The space between the exterior of Ithe casing and thewell bore wall may be sealed by a cement liner 4 and the casing mayterminate downwardly either to traverse the iluid containing formationor may end just above the formation. In the latter event, a smallerdiameter casing section 5 may be secured and sealed to the lower end ofthe casing 3 to project downwardly to line the bottom hole and forcommunication through lateral perforations 6 through the cement liner 1iwith the oil bearing stratum. As a part of the lower end of the stringof `tubing 2, there is a bottom length of pipe 7 which, at its upper endand above the producing formation, is surrounded by an annular packer toseal oft the well from the annulus space l. At its lower end, thedependent tubing section 7 has a bottom closure wall in which is mountedan inwardly opening standing valve 9 which opens for the inflow of wellfluid into the storage chamber lll afforded within the lower tubingsection, so long as the pressure within the chamber is less than bottomhole pressure. Whenever the pressure relationships are reversed, thestanding valve 9 closes against return flow from the chamber to thebottom hole.

An extension tube 11 is enclosed within and is of rsmaller diameter thanthe tube section 7 and at its upper end is secured and sealed olf by asuitable packer 12, with the tubing string a short distance above theannulus packer 8 so as to form a downward continuation of the productionstring extending downwardly thereto from the well head at the surface.At its lower end the extension tube il opens into the bottom of thestorage chamber l!) and co-operates therewith in receiving and storingwell uids and in providing an outlet from the storage chamber l0 whenpressure gas is applied into the: upper end of the storage chamber. Theco-operating walls of the tubing sections 7 and :il are imperforatethroughout their length and together with the top packer 12 seal off thechamber 1t) except for the communicating opening at the lower ends ofthe tubes 7 and 11 and except for a pipe or passage F connection 13 inby-passing relation with the packer 12 for communicating the upper endof the closed storage chamber 10 alternately with a vent port leading tothe interior of the tubing string 2 and a gas pressure supply passageafforded by one or more side wall ports 19a (FIG. 2B) through the wallof the tubing string and leading from the annular space 1. Suchcommunication is under control of an automatic valving assembly 14-which, in the case of FIG. l, is a retrievable unit which can be raisedor lowered through the tubing string and positioned in a laterallyoffset receiver positioned within an enlarged section `l5 of the tubingstring 2.

In place of a retrievable valve unit accessible from the tubinginterior, a valve unit llo, as shown in FIG. 5, may be mounted onexternal lugs 16 and 17 mounted on a production tubing section i8 andcontained within the surrounding annulus space. A connecting pipe 113communicates the top of a collecting chamber with the interior of thevalve body and is for alternate venting into the production tube 1Sthrough lateral ports 19 and for fluid pressure delivery from theannulus space through lateral ports 20.

Whether a retrievable valve unit as in FIG. 1 or a fixed mandrel unit asin FiG. 5, the detail control mechanism within the respective valvebodies is proposed, as best seen in FIGS. 2A and 2B. Here the valve bodyconveniently is made up of a succession of hollow or tubular sections14a, idf), 14e, Md, 14e and lief joined together at final assembly inend to end succession, as by means of threaded joints. As a retiievableunit, upper and lower packing rings Zl-Zl are clamped betweenco-operating body sections above and below a pressure gas entry port 22in the side wall of the body section 14e. In use, these packing ringsperipherally on spaced apart internal regions of the offset receiver ofthe tubing section l and provide seals above and below the entry port 22which is aligned with an annular internal groove formed in the receiverwall and provided with ported communication with the casing annulus l.Annular clearance between the wall and the inserted valve body above thepacking 21 communicates the interior of the production string 2 with alateral port or ports 23 of the body section idc for controlled ventingof the otherwise closed top of the storage chamber 10, as will later bedescribed. More particularly, the Vent port 23 is at the upper end ofinterior clearance space surrounding an elongated reciprocatory stern 24fitted within the body section 14e and which clearance constitutes aninterventing passage leading from a tapered valve seat 25 at the upperend of the space Z6 within a valve cage forming a part of the iiuidpassageway through the valve. in constant communication with the valvecage space 26 is a longitudinal port or passageway 27 extending throughthe skirt of a cupped piston 23 and opening into the bore or passageway2,9 extending downwardly through the body sections i4@ and 14f for opencommunication at all times with the upper end of the Weil fluid `storagechamber 1).

Above the side vent port 23, the body section 14C has an internal lug 3Ghaving slide bearing engagement with the stern 24 and mounting an O-ring31 for sealing between the adjoining slide bearing surfaces. As shown inFIG. 2A, a downwardly facing shoulder 32 on the stem Z4 is presentedwithin the vent port and its size may be controlled by design `so thatany head of Huid within the tubing string above the shoulder will exerta lifting force on the stern, which under some circumstances may bedesirable. The area may be diminished or increased in relation to othersurfaces carried by the valve stem for effecting imbalance or a balance.of opposing faces according to operating conditions in a particularwell.

Spaced upwardly from the sealed stem bearing lug 30 is an adapter member33 securely fastened as by means or" screw threads on the upper end ofthe Stem 24 and peripherally joined and sealed to the lower end of aiexible wall or metallic spring bellows 34 whose opposite end is sealedand joined to the bottom of the upper body or housing section 14a. Thehollow interior of the body portion i4@ is closed at its lower end bythe liexible wall 34 andthe upper surface of the valve stem adapter 33and is closed atrits upper end by an inwardly opening check valve 35athrough which the chamber may be charged with a pressure gas, preferablyone that is inert, such as nitrogen. The compressed gas provides anelastic spring toact on the adapter 33 for biasing the valve stemdownwardly. F or damping the rate of movement in either direction, ametering restriction or port 35 is provided in the lower end of atubular partition 36 carried by the housing rsection 14a to separate thechamber space into upper and lower divisions in communication onlythrough the constantly open orifice 35. In addition to the body ofcompressed gas, the chamber also confines a small liquid body, such assilicon oil, which separates by gravity from the gas and collects in thebottom of the chamber and to arlevel to extend intok the meteringorifice at the maximum expanded volume of the chamber. Chamber volumechanges will move the liquid in one direction or the other through therestricted orifice and control or damp the rate of change.

Since the liexible bellows wall encloses the upper side of the adapter33, there is provided an unbalance of surface area in the spacesurrounding the adapter and above the sealed bearing surface 30 and thedownwardly facing surfaces are of greater area. Such surrounding spacecommunicates through a lateral port 37 in the valve stem above thesealed bearing surface Sil with a longitudinal bore 3S extendingdownwardly in the stem and through a valve head or tip 39 at the lowerterminal of the stem. In the downwardly biased position of the parts,the head 39 has a downwardly facing hemispherical bottom surface inseating engagement with a downwardly tapered annular seat fil) at theupper internal corner of the circular skirt of the cupped piston 23. Thedownward areas of the adapter 33 and the valve tip 39 inwardly of theannular seat 4u are exposed to gas pressures within the hollow space ofthe cupped piston as communicated thereto through one or more lateralports il extended through the wall of the piston skirt in offset orcircularlyspaced relation with the longitudinal ports Z7. The two setsof ports may be formed by drilling round openings radially inwardly andlongitudinally downwardly respectively through ditierent regions of thepiston side wall or skirt. To the radial ports casing pressure gas flowsfrom the side ports Z?, by way of annular clearance space surroundingthe slide piston 2S and within the hollow body lids.

This `annular space about the piston is provided byari external steppedpiston diameter with downwardiy facing surface areas at verticallyspaced apart shoulders d2 and 43. The combined areas of these downwardlyfacing shoulders 42 and 43 exceed theY upwardly facing surface on thebottom wall 44 of the piston cup. Confined to these opposing faces, asin the FIG. 2B relationship, the pressure of lift gas supplied from thecasing annulus 1 through the ports 19a, Z2 and 41 and in opposition'tothe valve closing force, will act on the piston with a lifting tendencywhile the valve tip 39 is seated at {it} on the piston skirt, since theupper skirt surface is within the vented passage and is occluded fromaction thereon of annulus pressure gas.

When annulus pressure rises )and overcomes valve closing force, thepiston 2S follows the valve upwardly and maintains the seatingengagement at 4u until stopped by the limit abutment 47 immediately inadvance of vent closing engagement with the seat 25 by the upper seatshoulder 29 on the valve head. Separation from the seat 4h by the valveand its seating at 25 Occur in rapid succession and thereupon annulusgas pressure can act on the top surface of the piston skirt. Suchupwardly facing surface, either `alone or combined with the upwardlyfacing surface on the bottom cupped wall 44, presents an area in excessof the oppositely facing combined areas of the downward shoulders 42 and43, whereby the action of pressure gas on the differential areas willdepress the piston. A downward limit of piston movement is provided byIan upwardly facing shoulder 45 of a counterbored portion of the bodysection 14e and the lower edge of a depending skirt portion of thepiston which carries an 0-ring 46 for sealing purposes. The bottomsurface 47 of the body section 14d provides a stop to limit upwardtravel of the piston by engagement therewith (see FIG. 3) of the top ofthe piston skirt, whose peripheral upper portion has slide bearingengagement internally of the body section 14e and is sealed therewith byan 0- ring 48. The range of piston travel upwardly is slightly less thanthat of the Valve tip 39 on the head of the Valve stem 24. Thisvalvehead has an upwardly tapered seat 49 tov engage with the fixed annularvalve seat 25 as a stop to upward valve travel and for closing the valvecage from vented communication with the tubing interior..

During gas lift operation of the well and while the surface intermitteris closed against delivery of pressure gas to the casing annulus, thevulve parts will be in the position illustrated in FIGS. 2A and 2B,whereby the valve 39 seated at itl cuts off the gas annulus from thechamber llt) and the top of the chamber l@ is vented into the tubingstring 2 through the communicating passages 29, 27, 26 and 23 so thatwell liquids admitted past the Standing valve 9 can readily rise in thestorage chamber lll above the bottom of the production tube l1. When theintermitter delivers pressure gas, there will be a tendency for inwardgas flow through the inlet ports 22 land all, as aforesaid, and thepressure acting on the under sides of the piston and valve parts will beyieldingly opposed by the compressed gas within the flexible walledentrapment chamber and once the depressing7 force is overcome, both thepiston and the valve will rise toward the seat 25 'out with the seat 4t)remaining closed during the initial travel. Immediately the upwardtravel of the piston Z8 is stopped by the abutment 47, as seen in FiG.3, the continued rise of the valve under the pressure force will crackthe seal at the valve seat d@ and this action will take piace at aboutthe same time that the clearance around the valve seat 25 is beingrestricted, whereby pressure will build up above the top of the pistonskirt and reverse the direction of piston travel so that the piston andthe valve tip 39 both move away from each other for a free passage ofpressure gas from the entry port il and the valve cage space 26 `atapproximately the same time as the vent port 23 is closed at the upperlimit of valve travel by engagement of the complementary seatingsurfaces i9 and 25. With the separation of the seats 39 and and closureof the vent port 23, pressure of the casing lift gas can act on theupper face of the piston skirt within the cage space Z6 as well as onthe upward face of the piston wall 44 and, the piston will now movedownwardly from the upper limit of FIG. 3 to its lower limit, as shownin FIG. 4. From the Valve cage 26 and with the vent port Z3 remainingclosed, the lift gas moves downwardly through the piston passage 27 andthe body passage 29 into the top of the collecting chamber lil todepress the level of iuid therein and effect closing of the standingvalve 9 and a substantially complete evacuation of the liquid from thechamber l@ upwardly through tne open bottom of the tube il and onthrough the production tubing string 2 to the surface. After a selectedinterval of pressure gas delivery to the annulus il, the surfacecontroller will again shut oif further delivery of pressure gas and theresultant drop in pressure at the valve unit M- will allow the downwardbiasing force on the valve stem 24 to again do-minate and depress thevalve tip 39 into seating engagement with the annular seat ttl of thedepressed piston ZS, thereby sealing communication with the casing spacel and lowering the valve surface 49 from its seat 25 for repetition ofthe chamber venting phase of the cycle.

What is claimed is:

1. A pressure responsive valve assembly adapted for alternatelycommunicating the top of a well fluid collecting chamber with a ventmeans and a pressure gas supply source, comprising a valve elementhaving a stern and a head, an upwardly facing valve surface on the head,a downwardly facing valve surface on the head in axially spaced relationto the upwardly facing valve surface, a hollow housing enclosing andslidably mounting said stem, yieldable means carried by the housing andactive on the stem to bias the same downwarlly, a valve cageconstituting a part of the housing and surrounding said head, a chambercommunicating passage in the housing and opening into said valve cage, apressure gas supply passageway in the housing leading to and terminatingin an upwardly facing annular valve seat within the valve cage forengagement by said downwardly facing valve surface to close the supplypassageway under biasing action of said yieldable means, said valveelement having a downwardly facing area exposed to the passagewaysupplied pressure gas for passageway opening valve action in oppositionto said bias means and a vent passageway in the housing leading from andterminating at the valve cage in a downwardly facing annular valve seatfor engagement by said upwardly facing valve surface to close the ventpassageway in response to valve element movement upon action thereon ofsaid passageway supplied pressure gas.

2. A valve assembly as in claim l, wherein a piston carries the valveseat of the pressure gas supply passageway and is slidably mounted insaid cage, a downwardly facing surface on the piston exposed at alltimes lto said passageway supplied pressure gas and for response andupward travel with the valve element, piston engageable abutment meanscarried .by the housing to define a limit of upward piston travel withsaid valve element and Ito an extent less than valve element traveltoward said valve seat and an upwardly facing surface on Vthe piston andwithin said valve cage and of greater area than the area of saiddownwardly facing surface of the piston for exposure to passagewaysupplied pressure gas when upward piston travel is limited by saidabutment means so as to effect quick downward piston travel away fromsaid downwardly facing valve surface.

3. A well injection and vent valve assembly including a housing having axed valve seat, a vent passage surrounded by said valve seat andextended therefrom through the housing to the exterior thereof, a pistonslidably mounted in the housing for reciprocation toward and from saidfixed valve seat, a pressure gas entry passageway in the housing andprojected through the piston and into the space between the piston andsaid fixed valve seat, another passageway extending through the housingand opening into said space for alternate communication with the ventpassage and the pressure gas entry passageway, oppositely facingsurfaces on the piston adapted to be exposed to entry passageway `gaspressures and thereby control piston travel, a valve seat on one of saidsurfaces medially thereof to separate the same into two zones, a valveelement movably carried `by the housing within the space between .saidvalve seats and provided with :a surface exposed in said entrypassageway to pressure gas and movable in response thereto in adirection to engage and close said fixed valve seat, yieldable meanscontained in the housing and active on the valve element for biasing thesame in the direction to engage the valve element with the pistoncarried valve seat and thereby to exclude one of said two Zones fromaction -thereon of pressure gas, the other of said two zones having an:area less than that of the `surface facing oppositely thereto, so thatthe action on piston and valve element surfaces exposed to entrypassageway gas pressure in excess of yieldable means bias moves thevalve element toward said fixed seat and also moves the piston in`follow-up relation to the valve element and maintains the entry passageclosed in the initial portion of valve element travel, a housing carriedabutment engageable -by the piston as a limit stop to such follow-upmovement and for effecting opening of said entry passageway in the naltravel portion of the valve element into xed seat engagement, thecombined areas of said two zones exceeding the area of said oppositelyfacing surface and serving in response to pressure gas action lthereonto shift the piston away from the valve element.

4. A combined well injection and vent valve assembly including areciprocatory valve element `having axially spaced apart and oppositelyfacing valve seating surfaces, a housing slidably mounting the valveelement and providing a cage surrounding said seating surfaces, portmeans in said housing having constant communication with lthe interiorof said cage, a vent passage extending within the housing to theinterior thereof and leading from and having a xed valve seat at one endof the cage engageable 'by one of the valve seating surfaces to closethe vent passage and also to define one limit of spaanse reciprocationof the valve element, means on the valve element responsive to theaction thereon of pressure gas within the housing, a pressure gasdelivery passage projecting into the housing and leading to said cage, areciproc-atory piston slidably mounted in axial relation to said valveelement and within said cage and formed with a passage constituting apart of said gas delivery passage, oppositely facing surfaces on thepiston of differential areas, one surface being exposed within thedelivery passage and the other surface being exposed partly within thedelivery passage `and partly within said cage, a valve seat on thepiston surrounding the passage therein and engageable by the other ofsaid valve seating surfaces to occlude the ow of pressure gas into thecage, piston engageable stop means on the housinfy confining the rangeof piston movement to less than that of the valve element and yieldablemeans carried by the housing tand active on the valve element in adirection to bias the same into engagement with the piston in oppositionto action of pressure gas on the valve element and on the piston withinits range of valve engaging movement.

5. in a combined well injection and vent valve, a :housing having a flowpassageway and pressure `gas entry means thereto, a piston slidablymounted in the passageway and movable in response to the action ofpressure gas on oppositely `facing surfaces thereof, one of whichsurfaces is of larger area than the other, the larger surface beingdownstream and the smaller surface being upstream of the passage and inrelation one to another, piston engageable stop `surfaces on thehou-sing defining opposite ylimits of piston movement, a reciproca-toryvalve mounted in the housing for travel through a range greater than thetravel range of the piston and provided with a seating surface exposedwithin the passageway, a seat on said larger surface of the pistonengageable by said seating surface of the valve to seal the passagewaylagainst pressure gas fiow from said entry means and to occlude aportion of said larger surface from pressure gas action, said housinghaving la vent port therein leading from the passageway, a valve seat inthe housing surrounding the passageway vent port in downstream `relationwith the valve engageahle seat on the piston and being engageable bysaid valve for establishing a limit of travel therefor and for closingthe vent port, yieldable means carried by the housing Iand active on`the valve in the direction to seat the valve on said piston and resistmovement of the valve and the piston away from one limit of pistonmovement and yieldable in response to gas pressure for piston and valvemovement in downstream direction tto :the other limit of piston movementand for further valve movement out of engagement with the piston andinto engagement with the valve seat of the vent port.

6, ln a pressure responsive vent and gas injection valve for Wells, ahousing having a well communicating chamber, a pressure gas deliverypassage in said housing 4and leading to the chamber, a movable valvewithin the chamber having a surface exposed to pressure gas in :the

passage and responsive there-to for movement in downstream direction,yieldable means carried by the housing and active on the valve inopposition to pressure gas thereon, ta pair of spaced apart seats in thechamber alternately engageable by said valve at opposite limits thereof,one of said seats being xed in the housing to establish valve travellimit in downstream direction, said housing having a vent port thereinand surrounded by the last mentioned valve seat, la slidable pistoncontained in the chamber and carrying the other of said seats and havingoppositely yfacing surfaces of unequal areas for exposure to pressuregas, one of said surfaces being upstream `of the piston carried seat andresponsive to pressure gas to effect piston travel in follow-up relationto valve travel in downstream direction and the other of said surfaceshaving a portion thereof on the downstream side of the piston carriedseat to be occluded from action .thereon of pressure gas while the valveis engaged with the pis-ton carried seat and stop means engageable bythe piston Ito limit its downstream ltravel to less than valvedownstream travel, said other of said surfaces in relation to theoppositely facing surface presenting to the pressure ygas a smaller areawhile the valve is engaged with the piston and a larger area upondisengagement of the valve and piston.

7. 1n a pressure responsive vent and gas injection valve for wells, ahousing having a pressure gas flow passage, a pair of valve membersmovably mounted in the housing and one thereof comprising a headpositioned within the passage and having a surface exposed to pressure`gas action for response thereto in moving the head in downstreamdirection, yieldable means contained in the housing and active to resistsuch movement, oppositely facing seating surfaces on said head, saidhousing having a vent port therein leading from the passage, a fixedseat surrounding the vent port and engageable by the valve head to closethe port and .to limit valve head movement in downstream direction, theother of said valve members having a central opening forming a part ofsaid passageway and also having an annular valve seat surrounding thepassageway at one end and engageable by said valve head and oppositelyfacing surfaces on said other of the valve members, one in upstreamrelation to the annular valve seat and the other in downstream relationto the annular valve seat, the downstream surface being of larger areathan the upstream surface and said surfaces serving to control movementof said other valve member by exposure of the respective surfaces topressure gas within said passage.

References Cited in the tile of this patent UNITED STATES PATENTS1,794,427 White Mar. 31, 1931 2,142,484 Jennings Ian. 3, 1939 2,142,485Stephens Jan. 3, 1939 2,213,372 Aucoin Sept. 3, 1940 2,229,914 BoyntonJan. 28, 1941 2,556,867 `Carlisle June 12, 1951 2,573,110 Robinson Oct.30, 1951

